A companion document is at http://www.rogerclarke.com/SOS/InnDiffISW.html

Some inventions 'take the world by storm' (archetype: the Sony
Walkman).

Others seem to fail, lie dormant for decades, but when 'their time has come',
their use grows quickly, even explosively (archetype: the fax machine).

Most achieve slow penetration at first, then their adoption grows more quickly,
but later slows down again.

A broad social psychological / sociological theory called Diffusion of
Innovations (DoI) Theory purports to describe the patterns of adoption, explain
the mechanism, and assist in predicting whether and how a new invention will be
successful. It is expressed in Rogers E.M. 'Diffusion of Innovations' The
Free Press, New York, originally published in 1962, 3rd Edition 1983.

The theory has potential application to information technology ideas, artefacts
and techniques, and has been used as the theoretical basis for a number of IS
research projects. This document provides a brief overview of the elements of
the theory, intended as preparation for a reading of the relevant IS literature.

DoI Theory is concerned with the manner in which a new technological
idea, artefact or technique, or a new use of an old one, migrates from creation
to use. According to DoI theory, technological innovation is
communicated through particular channels, over time, among the members of a
social system.

The stages through which a technological innovation passes are:

knowledge (exposure to its existence, and understanding
of its functions);

persuasion (the forming of a favourable attitude to it);

decision (commitment to its adoption);

implementation (putting it to use); and

confirmation (reinforcement based on positive outcomes
from it).

Early knowers generally are more highly educated, have higher social status,
are more open to both mass media and interpersonal channels of communication,
and have more contact with change agents. Mass media channels
are relatively more important at the knowledge stage, whereas
interpersonal channels are relatively more important at the
persuasion stage.

Innovation decisions may be optional (where the person or organisation has a
real opportunity to adopt or reject the idea), collective (where a decision is
reached by consensus among the members of a system), or authority-based (where
a decision is imposed by another person or organisation which possesses
requisite power, status or technical expertise).

Important characteristics of an innovation include:

relative advantage (the degree to which it is perceived
to be better than what it supersedes);

trialability (the degree to which itcan be experimented
with on a limited basis);

observability (the visibility of its results).

Different adopter categories are identified as:

innovators (venturesome);

early adopters (respectable);

early majority (deliberate);

late majority (sceptical);

laggards (traditional).

Earlier adopting individuals tend not to be different in age, but to have
more years of education, higher social status and upward social mobility, be in
larger organisations, have greater empathy, less dogmatism, a greater ability
to deal with abstractions, greater rationality, greater intelligence, a greater
ability to cope with uncertainty and risk, higher aspirations, more contact
with other people, greater exposure to both mass media and interpersonal
communications channels and engage in more active information seeking.

Important roles in the innovation process include:

opinion leaders (who have relatively frequent informal
influence over the behaviour of others);

change agents (who positively influence innovation
decisions, by mediating between the change agency and the relevant social
system);

change aides (who complement the change agent, by having
more intensive contact with clients, and who have less competence credibility
but more safety or trustworthiness credibility).

The change agent functions are:

to develop a need for change on the part of the client;

to establish an information-exchange relationship;

to diagnose the client problems;

to create intent to change in the client;

to translate this intent into action;

to stabilise adoption and prevent discontinuance; and

to shift the client from reliance on the change agent to self-reliance.

DoI Theory is at its best as a descriptive tool, less strong in its
explanatory power, and less useful still in predicting outcomes, and providing
guidance as to how to accelerate the rate of adoption. There is doubt about
the extent to which it can give rise to readily refutable hypotheses. Many of
its elements may be specific to the culture in which it was derived (viz. North
America in the 1950s and 60s), and hence less relevant in, for example, East
Asian and African countries, and as time goes on.

Nonetheless, it provides one valuable 'hook' on which research and practice can
be hung.

The content and infrastructure for these community service pages are provided by Roger Clarke through his consultancy company, Xamax.

From the site's beginnings in August 1994 until February 2009, the infrastructure was provided by the Australian National University. During that time, the site accumulated close to 30 million hits. It passed 50 million in early 2015.